copy files from source to destination. e.g. cp /Users/mydir/README.txt ~/Documents
cp source destination
copy all folders, subfolders, and files from source to destination
cp -R source destination
move files or folders from source to destination (no need for -R)
mv source destination
move multiple files with the * wildcard, which copies all .rtf files. The tilde (~) symbol is a shortcut for your Home folder, which contains '/Desktop'.
cp ~/Desktop/*.rtf ~/Documents
rename files
mv ~/Desktop/MyFile.rtf ~/Desktop/MyFile-old.rtf
cp ~/Desktop/MyFile.rtf ~/Documents/MyFile-old.rtf